6700c no network on 900Mhz
 

6700c no network on 900Mhz(GSM). Phone works fine on 2100Mhz(UMTS). Any solution?

seems PA faulty , if u post here selftest result that would be better .

but anyway , before going to replace PA reflow or replace Z7521 & check . if still same then try to reflow or replace Z7523 (both rx-tx filters r marked in picture).

if again still same issue then replace PA with new one . post result.

Self tests

ST_CURRENT_CONS_TEST Yes Passed [ 0 ]
ST_EAR_DATA_LOOP_TEST No Passed [ 0 ]
ST_KEYBOARD_STUCK_TEST No Passed [ 0 ]
ST_SIM_CLK_LOOP_TEST Yes Passed [ 0 ]
ST_SLEEP_X_LOOP_TEST Yes Passed [ 0 ]
ST_KELVIN_VIBRA_TEST No Passed [ 0 ]
ST_BACKUP_BATT_TEST No Passed [ 0 ]
ST_LPRF_IF_TEST No Passed [ 0 ]
ST_CAMERA_IF_TEST No Passed [ 0 ]
ST_KELVIN_BATVOLTAGE_TEST No Passed [ 0 ]
ST_KELVIN_CAPACITOR_TEST No Passed [ 0 ]
ST_KELVIN_AUDIO_TEST No Passed [ 0 ]
ST_KELVIN_MISC_TEST No Failed [ 1 ]
ST_KELVIN_CHARGING_TEST No Passed [ 0 ]
ST_AMB_LIGHT_SENSOR_TEST No Passed [ 0 ]
ST_SIM_LOCK_TEST Yes Passed [ 0 ]
ST_CAMERA_AUTOFOCUS_TEST No Passed [ 0 ]
ST_LCD_TEST No Passed [ 0 ]
ST_LPRF_AUDIO_LINES_TEST No Passed [ 0 ]
ST_UEM_CBUS_IF_TEST Yes Passed [ 0 ]
ST_CDSP_SLEEPCLK_FREQ_TEST No Passed [ 0 ]
ST_BACKLIGHT_TEST Yes Passed [ 0 ]
ST_BT_WAKEUP_TEST No Passed [ 0 ]
ST_CDSP_TXC_DATA_TEST No Passed [ 0 ]
ST_CDSP_WCDMA_TX_POWER_TEST No Fatal [ 12 ]
ST_CDSP_GSM_TX_POWER_TEST No Fatal [ 12 ]
ST_CDSP_RX_PLL_PHASE_LOCK_TEST No Passed [ 0 ]
ST_CDSP_TX_PLL_PHASE_LOCK_TEST No Passed [ 0 ]
ST_CDSP_RX_IQ_LOOP_BACK_TEST No Passed [ 0 ]
ST_CDSP_RF_SUPPLY_TEST No Passed [ 0 ]
ST_CDSP_TX_IQ_TEST No Passed [ 0 ]
ST_CDSP_RF_BB_IF_TEST No Passed [ 0 ]
ST_TAHVOINT_TEST Yes Passed [ 0 ]
ST_PWR_KEY_TEST Yes Passed [ 0 ]
ST_USB_LOOP_TEST No Passed [ 0 ]
ST_SECURITY_TEST Yes Passed [ 0 ]
ST_BTEMP_TEST No Passed [ 0 ]
ST_ACCELEROMETER_TEST No Passed [ 0 ]
ST_DIGIMIC_TEST No Passed [ 0 ]
ST_LED_FLASH_TEST No Passed [ 0 ]
ST_CDSP_SLEEPCLOCK_FREQ_TEST No Passed [ 0 ]
ST_LED_CONTROLLER_TEST No Passed [ 0 ]
ST_USB_CHARGER_TEST No Passed [ 0 ]